The level of mental load during a functional task is reflected in oculometrics

Abstract

Modern occupations have increasingly become mentally demanding. This underlines the needs for investigation of the interaction of mental and physical workload. This study assessed the effects of mental load on ocular metrics and their consistency across days. Eighteen participants performed a five minute simulated computer work with three different levels of mental load in two days at least seven days apart. Eye movements in response to the task mental load level were recorded. Along with eye movements, task performance, and national aeronautics and space administration task load index (NASA-TLX) scores were acquired. Peak saccade velocity decreased, and pupil dilation range increased with the task load level and the response remained consistent across experimental days. Increased NASA-TLX score and reduced performance were in association with mental load demand. The study shows the feasibility of quantifying the mental load demands by monitoring oculometrics during a functional task such as computer work.